smoking weed during pregnancy does indeed effect the baby.
one of my older friends had a pregnancy and smoked weed at the same time, she gave birth and now 4 years later her son has yet to develop proper speach and understanding whereas his nursery school friends are all developing normally.
my advise would be to quit the weed full stop. if you need help then go to a clinic to get it. you could be doing your baby some real harm for later on in life.
you have to think about your baby now.
best of luck!